Microphone devices and methods for operating thereof

Abstract

A microphone device includes a number N of at least two serially coupled microphones forming a microphone chain. The microphones are configured to transmit data to a controller via the microphone chain. The microphone chain is configured to output time-multiplexed data transmitted by the microphones.

What is claimed is: 
     
       1. A microphone device, comprising:
 a number N of at least two serially coupled microphones forming a microphone chain, wherein:
 the microphones are configured to transmit data to a controller via the microphone chain, 
 each microphone, of the number N of at least two serially coupled microphones, comprises:
 a clock input for receiving an external clock signal, 
 a channel select pin for receiving data from a component arranged upstream of the microphone, and 
 a data output for transmitting data to a component arranged downstream of the microphone, and 
 
 the microphone chain is configured to output time-multiplexed data transmitted by the microphones. 
 
 
     
     
       2. The microphone device of  claim 1 , wherein:
 each of the number N of at least two serially coupled microphones is configured to receive the external clock signal provided by the controller, an external clock rate of the external clock signal being higher than a multiplexing clock rate, and 
 the number N of at least two serially coupled microphones are configured to transmit data to the controller via the microphone chain based on the external clock rate. 
 
     
     
       3. The microphone device of  claim 1 , wherein data transmitted from the number N of at least two serially coupled microphones to the controller is transmitted via a common serial data line. 
     
     
       4. The microphone device of  claim 2 , wherein for N consecutive clock periods of the external clock signal, an output of the microphone chain comprises data provided by each of the number N of at least two serially coupled microphones. 
     
     
       5. The microphone device of  claim 2  wherein transmitting data via the microphone chain to the controller is based on at least one of a rising edge of the external clock signal or a falling edge of the external clock signal. 
     
     
       6. The microphone device of  claim 2 , wherein a ratio of the external clock rate to the multiplexing clock rate is N or N/2. 
     
     
       7. The microphone device of  claim 2 , wherein each microphone, of the number N of at least two serially coupled microphones, transmits data at a rising edge of the external clock signal or each microphone, of the number N of at least two serially coupled microphones, transmits data at a falling edge of the external clock signal. 
     
     
       8. The microphone device of  claim 2 , wherein:
 a first number of maximum N/2 microphones, of the number N of at least two serially coupled microphones, transmits data at a falling edge of the external clock signal, and 
 a second number of maximum N/2 microphones, of the number N of at least two serially coupled microphones, transmits data at a rising edge of the external clock signal. 
 
     
     
       9. The microphone device of  claim 2 , wherein:
 each of the number N of at least two serially coupled microphones is configured to convert the external clock rate of the received external clock signal to the multiplexing clock rate, and 
 each of the number N of at least two serially coupled microphones is configured to perform internal audio processing is based on the multiplexing clock rate. 
 
     
     
       10. The microphone device of  claim 1 , wherein:
 a first microphone, of the number N of at least two serially coupled microphones, of the microphone chain is arranged at an end of the microphone chain, 
 the data output of the first microphone is configured to be coupled to the controller, and 
 the channel select pin of the first microphone is coupled to the data output of a microphone, of the number N of at least two serially coupled microphones, arranged upstream of the first microphone. 
 
     
     
       11. The microphone device of  claim 10 , wherein:
 an N-th microphone, of the number N of at least two serially coupled microphones, of the microphone chain is arranged at an opposite end of the microphone chain, 
 the channel select pin of the N-th microphone is coupled to a defined potential, and 
 the data output of the N-th microphone is coupled to the channel select pin of a microphone, of the number N of at least two serially coupled microphones, arranged downstream of the N-th microphone. 
 
     
     
       12. The microphone device of  claim 11 , wherein in intermediate microphone, of the number N of at least two serially coupled microphones, of the microphone chain arranged between the first microphone and the N-th microphone comprises:
 the channel select pin coupled to the data output of a microphone, of the number N of at least two serially coupled microphones, arranged upstream of the intermediate microphone, and 
 the data output coupled to the channel select pin of a microphone, of the number N of at least two serially coupled microphones, arranged downstream of the intermediate microphone. 
 
     
     
       13. The microphone device of  claim 1 , wherein a coupling between the number N of at least two serially coupled microphones and the controller is based on a pulse density modulation interface. 
     
     
       14. The microphone device of  claim 1 , wherein 2≤N≤8. 
     
     
       15. The microphone device of  claim 1 , wherein the microphone device is configured to be part of a speech application. 
     
     
       16. The microphone device of  claim 1 , wherein the microphone device is configured to be part of an active noise cancellation application. 
     
     
       17. The microphone device of  claim 1 , wherein the microphone device is configured to be part of an automotive application. 
     
     
       18. A method for operating a microphone device comprising a number N of at least two serially coupled microphones forming a microphone chain, wherein the method comprises:
 transmitting data from the number N of at least two serially coupled microphones to a controller via the microphone chain, wherein the microphone chain is configured to output time-multiplexed data transmitted by the microphones, and wherein each microphone, of the number N of at least two serially coupled microphones, comprises a channel select pin for receiving data from a component arranged upstream of the microphone, a data input for receiving data from a component arranged upstream of the microphone, and a data output for transmitting data to a component arranged downstream of the microphone. 
 
     
     
       19. A microphone device, comprising:
 a number N of at least two serially coupled microphones forming a microphone chain, wherein:
 the microphones are configured to transmit data to a controller via the microphone chain, 
 each microphone, of the number N of at least two serially coupled microphones, is configured to receive an external clock signal provided by the controller, an external clock rate of the external clock signal being higher than a multiplexing clock rate, and 
 the number N of at least two serially coupled microphones are configured to transmit data to the controller via the microphone chain based on the external clock rate. 
 
 
     
     
       20. The microphone device of  claim 19 , wherein data transmitted from the number N of at least two serially coupled microphones to the controller is transmitted via a common serial data line.